Research shows one ‘bad apple’ spoils the work of a team

One underperforming member, or ‘bad apple’, can spoil the work of a whole team, according to research being presented this weekend at the 9th Industrial and Organisational Psychology Conference (IOP) in Brisbane, hosted by the Australian Psychological Society College of Organisational Psychologists.

Lead researcher Benjamin Walker, from the University of New South Wales, examined the conscientiousness of team members, testing the notion that ‘one bad apple spoils the barrel’.

The study – of 158 students divided into 33 teams – set out to uncover how conscientiousness, the level of dedication and hard work of individual team members affected the work of the entire group.

“Conscientiousness has two sides to it: one is discipline and a need for achievement and the other is being painstaking and careful,” Mr Walker said.

“We found that a single lazy person – someone low in proactivity – drags the team down, reducing its satisfaction and performance,” he said.

While impulsiveness was seen as another potential negative for teams, the research found a single impulsive – low on cautiousness – team member did not reduce the overall satisfaction and performance in a team.

Previous research has examined the average level of particular personality traits within teams. However, this research shows that just a single member low in a particular personality trait can reduce performance and satisfaction.

“It was previously thought that the average level of a personality trait in a team defined its success,” Mr Walker said. “These findings show the person who contributes the least has a huge impact. Even if on average the rest of the team is pulling their weight, they won’t be able to compensate for that member and they won’t be happy about it.”


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About IOP: The ninth biennial Industrial and Organisational Psychology Conference, hosted by the Australian Psychological Society College of Organisational Psychologists, will be held in Brisbane from 23 to 26 June. It will explore current workplace issues such as leadership, stigma, workplace bullying, work/life balance, safety and mental health in the workplace. For a full program, go to